In this post, Lars Christie discusses his recent article in the Causation in War Symposium in Journal of Applied Philosophy on why causal responsibility is not a requirement for individual liability to defensive harm.

The traditional view in just war theory has been to distinguish sharply between combatants and non-combatants, holding that the latter group is immune from intentional targeting in war, whereas the former can be targeted without further discrimination.  A new revisionist position in contemporary just war theory rejects this view and the underlying concept of collective liability on which it rests.  According to the revisionist view, whether a person is liable to attack depends solely on their individual moral responsibility for causally contributing to an unjust threat.

A familiar criticism of the revisionist view is that it is too permissive. Since many non-combatants are responsible for individual contributions to the war the revisionist view counterintuitively rules many non-combatants liable to attack. In my article, I present a new and different worry. If causal responsibility is a requirement on individual liability, then many combatants will escape liability to defensive harm, because their actions do not in fact causally contribute to the war. This implication makes the revisionist view too restrictive, or so I argue.

In the article, I challenge accounts that hold causal contribution to an unjust threat as a requirement on liability to defensive harm. I consider cases where two or more individuals behave in identical ways, but only one poses a threat because of causal factors beyond her control. How can it be fair that only one of them ends up liable, while the other(s) escape(s) liability to defensive harm altogether? One way in which philosophers such as Jeff McMahan and Michael Otsuka have defended this view against the charge of unfairness, is to argue that by acting in ways we know impose a risk of unjust harm, we engage in type of a ”moral gamble”. As with other gambles, the argument goes, it is fair that those who participate are made to bear the relevant costs when they lose, even if the difference between winning and losing is purely a matter of luck.

The gamble analogy, however, is misleading. A minimal requirement of a fair gamble is that the gambler understands that she is taking a gamble and understands what counts as winning and losing. In the case of moral liability to defensive harm, there is no common understanding of the rules which determine what counts as winning and losing (where losing means becoming liable to defensive harm). Indeed, this is precisely the issue under debate. Presupposing an agreement to the rules of the “moral gamble” would settle this debate by assertion and not by argument.

I consider an attempt to appeal to desert‐based considerations to vindicate the conclusion that it is permissible to inflict defensive harm on culpable attackers who fail to be causally efficacious in posing a threat (I refer to such agents as futile attackers). This argument, if successful, would explain apparent counter-examples to the causal accounts of liability where it seems intuitively permissible to harm a futile attacker in the course of defending oneself against multiple attackers.  Although futile attackers may not be liable to defensive harm, adherents of causal accounts of liability could argue that it would still be permissible to harm such attackers because futile attackers deserve harm.  I argue that this strategy leads to more problems than it solves. If we accept that one may impose desert based harm on futile attackers, we must also accept that desert can add to the amount of harm it is permissible to impose on real attackers who are liable to defensive harm. This, however, would mean that responsibility for the same wrongful threat would count twice over: first to trigger or increase liability to defensive harm and secondly to justify the additional infliction of deserved harm.

Denying that causal responsibility is a requirement on liability to defensive harm, as I argue in the article, has clear implications for the revisionist account of just war theory. Some combatants fighting an unjust war are utterly incompetent, some have faulty equipment, others are ordered on missions that are futile or even counter – productive. If the causal account of liability were right, such combatants are not liable to defensive harm, and attacks that do not discriminate between them and their causally effective counterparts would not be justified. Once we accept my argument, however, revisionist theorist can arrive at the more plausible conclusion that combatants who are morally responsible for making an effort to contribute to an unjust war are liable to defensive harm, regardless of their actual individual causal contribution.

The Journal of Applied Philosophy is a unique forum for philosophical research that seeks to make a constructive contribution to problems of practical concern. Open to the expression of diverse viewpoints, it brings the identification, justification, and discussion of values to bear on a broad spectrum of issues in environment, medicine, science, policy, law, politics, economics and education. The journal publishes in all areas of applied philosophy, and posts accessible summaries of its recent articles on Justice Everywhere.